scholarly journals Chemically Thinning Spur `Delicious' Apples with Carbaryl, NAA, and Ethephon at Various Stages of Fruit Development

1996 ◽  
Vol 6 (3) ◽  
pp. 241-246 ◽  
Author(s):  
Richard P. Marini
Keyword(s):  
Acetic Acid ◽  
Fruit Development ◽  
Fruit Set ◽  
Naphthalene Acetic Acid ◽  
Full Bloom ◽  
Fruit Thinning ◽  
Repeated Applications ◽  
Fruit Diameter

Chemical fruit thinners were applied to limbs or whole trees of spur `Delicious' at various stages of fruit development as indicated by fruit diameter. Carbaryl, naphthalene acetic acid (NAA), and ethephon all reduced fruit set when applied at a fruit diameter of ≈4 to 15 mm. Fruit thinning for NAA and carbaryl, alone or combined, generally was greater when applied at an average fruit diameter of 8 mm, rather than at 4 mm. Repeated applications of NAA or carbaryl were no more effective than single applications. NAA + carbaryl applied at 9 mm was more effective than NAA applied at 4 mm followed by carbaryl at 8 mm. Applied when fruit diameter averaged 17 to 22 mm, ethephon and ethephon + carbaryl were effective fruit thinners. When applied at full bloom to ≈10 and 20 mm, the insecticides ethion and oxamyl, respectively, were effective fruit thinners.

scholarly journals Commercial-scale Use of Hydrogen Cyanamide for Apple and Peach Blossom Thinning

1998 ◽  
Vol 8 (4) ◽  
pp. 556-560 ◽  
Author(s):  
Esmaeil Fallahi ◽  
Randy R. Lee ◽  
Gary A. Lee
Keyword(s):  
Acetic Acid ◽  
Prunus Persica ◽  
Fruit Set ◽  
Fruit Size ◽  
Naphthalene Acetic Acid ◽  
Full Bloom ◽  
Hydrogen Cyanamide ◽  
Air Blast ◽  
Fruit Thinning ◽  
Commercial Scale

Hydrogen cyanamide (Dormex, 50% a.i.) for blossom thinning `Early Spur Rome' and `Law Rome' apple (Malus×domestica Borkh.) and `Flavorcrest' peach (Prunus persica L.) was applied with air-blast sprayers on a commercial scale. Full-bloom applications of hydrogen cyanamide at 4 pts formulation per 200 gal/acre (1288 mg·L−1) and 5 pts formulation per 200 gal/acre (1610 mg·L−1) significantly reduced fruit set in apple and peach. In `Early Spur Rome', a postbloom application of carbaryl [Sevin XLR Plus, 4 lb a.i./gal (0.48 kg·L−1)] following a full-bloom spray of hydrogen cyanamide increased fruit thinning with a significant increase in fruit size compared to an application of hydrogen cyanamide alone. In `Law Rome', trees receiving a full-bloom application of hydrogen cyanamide followed by a postbloom application of 1-naphthyl-N-methylcarbamate (carbaryl) + naphthalene acetic acid (NAA) had significantly lower fruit set and larger fruit than those in the carbaryl + NAA treatment. Apples or peaches were not marked by hydrogen cyanamide.

scholarly journals METAMITRON REPLACING CARBARYL IN POST BLOOM THINNING OF APPLE TREES

2016 ◽  
Vol 38 (4) ◽  
Author(s):  
JOSÉ LUIZ PETRI ◽  
MARCELO COUTO ◽  
GENTIL CARNEIRO GABARDO ◽  
POLIANA FRANCESCATTO ◽  
FERNANDO JOSÉ HAWERROTH
Keyword(s):  
Acetic Acid ◽  
Experimental Design ◽  
Standard Treatment ◽  
Fruit Set ◽  
Naphthalene Acetic Acid ◽  
Single Plant ◽  
Fresh Weight ◽  
Apple Trees ◽  
Fruit Thinning ◽  
Apple Cultivars

ABSTRACT Carbaryl or the mixture of carbaryl with NAA (naphthalene acetic acid) or BA (benzyladenine) are the post-bloom chemical thinners most widely used in apple thinning in Brazil. The marketing restriction of carbaryl demands new options of apple post-bloom thinners, requiring the evaluation of others compounds for this purpose. Metamitron is one of the substances that may be used in chemical thinning of apples. Metamitron was evaluated at two concentrations, alone or in mixture with BA, in ‘MaxiGala’, ‘Fuji Suprema’ and ‘Fred Hough’ apple cultivars. Applications of metamitron at 384 mg L-1 and at 768 mg L-1 in a mixture with BA, ranging from 40 mg L-1 to 80 mg L-1, sprayed on fruits with diameter ranging from 5 to 25 mm were compared with the standard treatment and hand thinning. The experimental design was a randomized complete block with 4-6 repetitions of a single plant. The variables analyzed were: fruit set (%); percentage of floral clusters with 1, 2, 3, 4 or more fruits; fruit yield (kg); average fruit fresh mass (g) and percentage of dropped fruit after thinning. Metamitron alone or in combination with BA reduced production per plant and significantly increased the fresh weight of fruits in all cultivars tested. Metamitron at 800 mg L-1 resulted in excessive fruit thinning, especially in ‘MaxiGala’ cultivar. Metamitron or metamitron + BA have potential to compose the program of chemical thinning of apple trees to replace carbaryl.

scholarly journals (99) Using Naphthalene Acetic Acid, Prohexadione-Ca, Ethephon, and Scoring to Reduce Vegetative Growth in Upper Canopy of Apple Trees

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1030C-1030
Author(s):  
Wesley R. Autio ◽  
James Krupa ◽  
Jon M. Clements ◽  
Duane W. Greene
Keyword(s):  
Acetic Acid ◽  
Vegetative Growth ◽  
Shoot Growth ◽  
Fruit Set ◽  
Extension Growth ◽  
Naphthalene Acetic Acid ◽  
Full Bloom ◽  
Treatment Area ◽  
Latex Paint ◽  
Apple Trees

In 2004, at full bloom, 3-year-old `Cameo'/G.16, `Gala'/M.9 NA-KBT337, `Gala'/G.16, and `Redmax'/B.9 apple trees were treated with naphthalene acetic acid (NAA, 1.5% in latex paint) in a 7.5-cm band completely around the central leader at the base of 2-year-old wood. NAA treatment reduced 2004 extension growth of the central leader by 14% and total shoot growth above the treatment area by 32%. `Cameo'/G.16 trees also were sprayed with prohexadione-Ca (250 ppm with surfactant and water conditioner) at full bloom, and additional trees were sprayed with ethephon (500 ppm with surfactant) 1 week after full bloom. These spray treatments were made only to the stems and foliage from the base of the central leader's 2-year-old wood to the top of the canopy. Ethephon reduced total shoot growth in 2004 by 26%, and prohexadione-Ca reduced it by 63%. Prohexadione-Ca also reduced fruit set of `Cameo' in 2004. Scoring (single knife cut completely around the circumference of the trunk) at the base of the 2-year-old wood in the `Cameo' trees resulted in a 23% reduction in leader growth and a 22% in totals shoot growth in the upper canopy in 2004. In 2005 at full bloom, 4-year-old `Golden Delicous'/B.9 trees were treated with NAA similarly to trees in 2004, except treatment at the base of 2-year-old wood was compared to treatment at the base of 1-year-old wood. Treating the base of 1-year-old wood reduced growth to a greater degree than comparable treatment at the base of 2-year-old wood. For the 1- and 2-year-old-wood treatments, the number of laterals produced from the 1-year-old wood was reduced 42% and 17%, and total shoot growth from 1-year-old wood was reduced by 49% and 31%, respectively.

Control of premature fruit drop in Macadamia integrifolia: effects of naphthalene acetic acid application, cincturing, and shoot-tip removal

1980 ◽  
Vol 20 (107) ◽  
pp. 740 ◽  
Author(s):  
RR Williams
Keyword(s):  
Acetic Acid ◽  
Fruit Set ◽  
Shoot Tip ◽  
Naphthalene Acetic Acid ◽  
Fruit Drop ◽  
Macadamia Integrifolia

The effects of NAA application, cincturing and shoot-tip removal on the incidence of premature fruit drop were investigated in orchard-grown trees of Macadamia integrifolia cv. Kakea. A single, post-anthesis application of NAA (1 ppm) increased (P < 0.05) the final set of macadamia fruit by 35%. Limb cincturing combined with shoot-tip removal increased (P < 0.05) initial fruit set and possibly final set. Cincturing alone was less effective and shoot-tip removal had no effect alone.

Studies on the fruit thinning effect of N.A.A. and some carbamates on Jonathan and Delicious apples

1975 ◽  
Vol 15 (74) ◽  
pp. 424
Author(s):  
N Veinbrants
Keyword(s):  
Fruit Set ◽  
Full Bloom ◽  
Time Of Application ◽  
Fruit Thinning ◽  
Bloom Period ◽  
Series Of Experiments ◽  
Thinning Effect

In a series of experiments in Victoria a single spray of the fungicide thiram applied shortly after full bloom reduced fruit density highly significantly on Jonathan and Delicious apples, but resulted in insufficient thinning. The fungicide Dithane M-45 caused mild thinning and the fungicide Dikar had no effect on fruit set when applied during post-bloom period on Jonathan apples. Applications of the insecticide carbamult applied 16, 23 and 32 days after full bloom reduced fruit density highly significantly and to about the extent as N.A.A. applied 16 days after full bloom on Jonathan apples. Carbamult caused the same degree of thinning irrespective of time of application. N.A.A. and carbamult resulted in adequate fruit thinning.

Thinning Golden Delicious apples with pre-bloom naphthalene acetic acid and later carbaryl sprays

1984 ◽  
Vol 24 (126) ◽  
pp. 453 ◽  
Author(s):  
KM Jones ◽  
TB Koen ◽  
RJ Meredith
Keyword(s):  
Acetic Acid ◽  
Fruit Size ◽  
Fruit Weight ◽  
Naphthalene Acetic Acid ◽  
Full Bloom ◽  
Golden Delicious

A trial in southern Tasmania examined the thinning effects of naphthalene acetic acid (NAA) on Golden Delicious apples. The NAA was applied at pink bud or balloon blossom at 12, 18 and 24 ppm, with or without carbaryl at 1800 ppm applied 10 d after full bloom. Carbaryl was also applied alone 10 and 20 d after full bloom, and a hand thinned treatment was included. The higher concentrations of NAA did the most thinning but only the hand-thinned and 24 ppm NAA at balloon blossom with carbaryl treatment thinned enough to produce the required fruit size. The NAA sprays at balloon blossom thinned considerably more than those at pink bud. Neither NAA nor carbaryl alone was as effective as the combination. Reduction of fruit numbers increased mean fruit weight from 101 g in the control to 149 g in the 24 ppm NAA at balloon blossom with carbaryl. There was no evidence that increasing the concentration of NAA reduced mean fruit weight. This trial demonstrates that the effect of balloon stage sprays of NAA combined with later carbaryl sprays on Golden Delicious is similar to that achieved by the normal practice of spraying with NAA 7-14 d after full blossom, followed by carbaryl at 20 d. Reduction from 128 fruit/ 100 blossom clusters in the control to 76 after spraying at balloon blossom is still outside present aims of 30-50 fruit and is not considered to be severe enough thinning to assure adequate fruit size.

Control of pudding spot in Crofton apple

1992 ◽  
Vol 32 (4) ◽  
pp. 503
Author(s):  
KM Jones ◽  
SA Bound ◽  
MJ Oakford ◽  
TB Koen
Keyword(s):  
Acetic Acid ◽  
Fruit Size ◽  
Fruit Weight ◽  
The Other ◽  
Naphthalene Acetic Acid ◽  
Full Bloom ◽  
Apple Trees ◽  
Low Incidence ◽  
Thinning Effect

Regularly cropped Crofton apple trees in southern Tasmania were thinned using sprays of naphthalene acetic acid (NAA) at 10 mg/L or ethephon at 200 mg/L at balloon blossom (BB), full bloom (FB), 10 days after full bloom (DAFB) or 20 DAFB. These treatments were compared with hand thinning and an unthinned control. Ethephon had a uniformly mild thinning effect (about 30% compared to control), except at 10 DAFB, where no thinning occurred. NAA was inconsistent, thinning well at BB (50%), overthinning at both FB (85%) and 10 DAFB (88%), and underthinning at 20 DAFB (similar to the control). Ethephon applied at BB and FB increased both mean fruit weight (12 and 22%) and fruit size (28 and 79%), but later applications did not. NAA applications generally resulted in increased mean fruit weight and size, except for the 20 DAFB treatment, which was similar to the control. All ethephon treatments had a low incidence (43%) of pudding spot similar to the controls and hand-thinned treatments. Most NAA treatments showed significantly higher levels of pudding spot than the other treatments. It is concluded that ethephon is a more predictable thinner for Crofton than NAA, and its use to control pudding spot is recommended.

Effect of timing of hand thinning on productivity of Moorpark apricots destined for drying

1999 ◽  
Vol 39 (7) ◽  
pp. 885 ◽  
Author(s):  
M. A. Rettke ◽  
A. P. Dahlenburg
Keyword(s):  
Fruit Development ◽  
South Australia ◽  
Fruit Weight ◽  
Fresh Fruit ◽  
Soluble Solids ◽  
Full Bloom ◽  
Total Soluble Solids ◽  
Fruit Thinning ◽  
Dried Fruit ◽  
Fruit Stone

Summary. Thinning at full bloom was compared with thinning at 3 stages of fruit development and the effects on size, total soluble solids level (TSS) and yield of apricots are reported. In 2 seasons separate branches of 9-year-old Moorpark apricot trees were hand-thinned to a density of 1 blossom or fruit per 50 mm of fruiting wood. Times of thinning were at full bloom, 5–15 mm size fruit, stone tip hardening and 21 days post stone tip hardening. These treatments were compared with an unthinned control. Experimentation was carried out at Loxton, South Australia. All thinning treatments reduced the yield of fresh fruit. Thinning reduced yield of dried fruit irrespective of timing in the first season but only at the 5–15 mm diameter fruit timing in the second season. Total soluble solids level of the fruit was increased by thinning which tended to improve drying ratio. Compared to the unthinned control all thinning treatments increased the size of fresh fruit. Mean fruit weight and diameter progressively decreased as thinning was delayed from full bloom till stone tip hardening. Thinning at full bloom produced higher yields of 35-mm-grade dried fruit than other treatments. To achieve the greatest benefit from thinning it should be carried out at blossoming.

scholarly journals EFFECTS OF HYDROGEN CYANAMIDE ON APPLE AND PLUM FRUIT THINNING

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 690a-690
Author(s):  
Esmaeil Fallahi ◽  
Brenda R. Simons ◽  
John K. Fellman ◽  
W. Michael Colt
Keyword(s):  
Malus Domestica ◽  
Fruit Set ◽  
Fruit Size ◽  
Apple Fruit ◽  
Fruit Weight ◽  
Full Bloom ◽  
Hydrogen Cyanamide ◽  
Fruit Thinning ◽  
Prunus Salicina

Influence of various concentrations of hydrogen cyanamide (HC) on fruit thinning of `Rome Beauty' apple (Malus domestica Borkh.), `Friar,' and `Simka' plums (Prunus salicina Lindley) were studied. A full bloom application of HC at all tested concentrations decreased `Rome Beauty' apple fruit set and yield, and increased fruit weight. Hydrogen cyanamide at 0.25% (V/V) resulted in adequate apple thinning, indicated by the production of an ideal fruit weight. Prebloom and full bloom applications of HC at greater than 0.75% reduced plum fruit set and yield in `Friar.' Full bloom application of HC at 0.25% to 0.50% showed a satisfactory fruit set, yield, and fruit size in `Friar' plum. Full bloom application decreased fruit set and yield in `Simka' plum. Hand thinning, as well as chemical thinning, is recommended for plums.

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